Garments such as briefs or panties have been made by knitting a tubular blank on a circular knitting machine and cutting out areas on opposite sides that form leg openings when the front and rear ends of the blank are sewn together. As described in U.S. Pat. No. 4,628,115, guide lines for the cutting operation may be formed in the blank by a distinctive stitch such as a tuck stitch in a jersey knit or by knitting the entire area to be cut out with a distinctive stitch so that the line of demarcation between it and the rest of the blank serves as a cutting guide. It is estimated that the process wastes about 20% of the yarn depending on the particular design of the brief or panty. In the highly competitive garment industry this amount of waste is very significant.
As described in U.S. Pat. No. 4,043,156, this waste is substantially eliminated by knitting the blank with a shape that does not require cutting. In particular, an elastic waistband is knit in the form of a transfer or double welt. Then a number of complete circular courses are knit so as to form a body section, and front and rear panels are knit to the body section. The width of each panel is reduced as the knitting proceeds so as to provide the shape required for the leg opening. This is done by successively casting off yarn from needles located between the panels. At the end of the tapered section thus formed an untapered end section is knit to each panel having parallel sides along given wales. The brief or panty is made by overlapping the untapered end sections and sewing them together to form the leg openings. As the casting off operation leaves yarn ends or floats along the edges of the panels, it is necessary to sew a width of trimming material along the edges of the leg openings.
Whereas this method of making briefs or panties reduces the amount of wasted yarn, it inherently slows the rate of production. Furthermore, the tapered edges of the panels curl so as to make it difficult to sew the trimming to the edges of the leg openings.